Ground strap question for 1966

[Ian S.]

Hello,

I have checked the archives and the AIM and I can't find the answer to this question. My very late build 66 has a 13 1/2 inch copper ground strap that goes from the top inside mounting bolt of the steering column on the firewall to the same rear intake manifold bolt that the accelerator ground strap attaches to. Any ideas what this is for and where I can find a new one.

Thank you,

Ian Spanic

[John H.]

Re: Ground strap question for 1966

Ian -

Sounds to me like a previous owner-inspired addition; I've never seen such a strap either.

[Joe C.]

Re: Ground strap question for 1966

Ian:

The ground continuity for the horn button was originally via a thin copper ribbon between the halves of the steering coupler ('rag joint"). That was probably compromised, so "bubba" made a quick, and effective fix. "Bubba" might have been an engineer, but he was not an NCRS judge.

Joe

[Ian S.]

Re: Ground strap question for 1966

That was going to be my next question. I had seen something about a ground strap and the horn button but was not sure exactly where it was. Is there a correct way to fix this if that is what happened?

Ian

[Joe C.]

Re: Ground strap question for 1966

Ian:

Remove "Bubba's" ground strap and see if the horn still works. If not, then the ground between the 2 halves of the rag is indeed broken. Originally, this is a very thin bare copper ribbon, about 3/32" wide. It is very hard to see, but with a good light, you should be able to spot it. Check for continuity between the 2 halves of the rag, with an ohmmeter.

To fix it, you have three options:

1. Reinstall "Bubba's" ground strap.
2. Purchase a new/reconditioned steering coupler.
3. Rebuild yours, or send it out for rebuilding.

If you rebuild it yourself, the trick part is to fashion the proper rivets, and then heat and correctly flatten them without destroying the rubber "rag". I did mine myself.......but unless you are skillful, I would send it out. You will also have to buy a new ground ribbon, and install it before you rivet the 2 halves together.

If you don't need a "concours" job, then a generic rebuild kit is available, but you will STILL have to purchase the "ribbon" seperately.

PS: The 1966 model does not use the plastic bushings on the pins, as in 1967.

Joe

[John H.]

Re: Ground strap question for 1966

The confusion continues relative to the plastic "bushings" on the rag joint safety pins; they were an assembly aid, to properly align the upper and lower flanges relative to each other and to maintain centering of the pins in the corresponding flange openings until the steering column system was fully secured after body drop. Once the column attachments were all secured, including the toe pan support and clamp, they were removed and pitched in a trash can. Leaving them in place will eventually result in noise and vibration being transmitted into the steering column as the "rag" carcass becomes more flexible and the O.D. of the plastic bushings begin to make contact with the I.D. of the openings in the upper flange. In later years, the bushings had a "leg" on them with a hole in it to simplify removal on the line with a "hook" tool.

[Scott S.]

Re: Ground strap question for 1966

I have the same ground strap on my Feb 65 roadster, is this possible? Many of the cars I look at for "tips" don't have it. I haven't been able to find it in my assembly manual. Help?

[Joe C.]

Re: Ground strap question for 1966

What you have on your car will work. But if you want your Corvette to be "as delivered', then purchase the Technical Information Manual & Judging Guide AND the Assembly Manual for your car. Both are available on this website.

[Ian S.]

Re: Ground strap question for 1966

The one on my car looks exactly like all the other original ground straps right down to the connectors and patina. Was this material available in the past from GM so that you could make ground straps? Could these have been offered at Chevy dealers as a fix under warranty?

[Joe C.]

That Is Sound Enginering

Those with a 1967 TIM&JG will have the last word here. Not being a 1967 expert, I'm only passing on information garnered from 1967 owners.

From a practical standpoint, I can't see the usefulness of plastic bushings on the limit pins.

[John H.]

Re: Ground strap question for 1966

Ian -

Those woven copper ground strap configurations were made in literally hundreds of lengths, with many different combinations of terminals; gazillions of them were made, and continue to be made today. The one you describe was most likely added to make the horn functional either when the original ground in the rag joint corroded away, or the rag joint was replaced with a non-GM replacement part that didn't have the internal ground.